1. Field of the Invention
The present invention relates to a method and apparatus for making an external cutting member of an electric razor and more particularly to a method and apparatus for opening slits in the external cutting member of an electric razor.
2. Prior Art
Japanese Patent Application Publication (Kokoku) No. 41-14339 discloses an external cutting member for an electric razor that has two concentric circular shaving sections.
The external cutting member of this prior art has a partition groove that divides the shaving surface into inner and outer circular shaving sections. The partition groove is an angled-U-shape in cross section. The two shaving sections obtained by the partition groove are formed with many slits which open in a radial direction.
Since the partition groove that divides the shaving surface has sharp edges, pieces of hair and grease from the skin tend to accumulate in the partition groove, thus making it insanitary. In addition, the process for making the angled-U-shaped groove is troublesome.
Furthermore, the hair that enters into the partition groove may be bent when it comes into contact with the bottom of the groove. As a result, a smooth shaving is often hindered.
On the other hand, while the external cutting member as described above may be made by pressing, it is difficult to form the slits with high precision.